The autumn and winter of 2016 will long be remembered by birders across the UK, with the weather, as usual, having an influence upon the birds being seen in the country. There are many birds that I could pick to focus on when considering autumn 2016, all of which are from Siberia. However, I thought I’d discuss the recent Waxwing winter instead, as the weather has had a particularly interesting role in it, especially for birders in the south of the country.
Waxwings are an irruptive species and the last irruption was the winter of 2012/13, below are a couple of photographs of one of the many Waxwings that I photographed during the last irruption.
The 2012 irruption was fairly straight forward with birders across the country seeing or finding their own flocks as the wind direction was light or consistently from a N to E direction allowing the birds to come across. This time, however, things have been a bit more interesting from a meteorological perspective.
To be fair I should be focusing on what the weather was like in Scandinavia over the summer and the impact on the Rowan berry harvest and what the status of the Waxwing population, as the invasions are strongly linked to food supply and population size. However, I’m going to purely focus on the movement towards (and around) the UK. So, to start off we need to consider what the weather was like when the Waxwings were first arriving, back in late October 2016.
Back in October there was a constant easterly air flow, implying that there was not a head wind for any birds coming across from the continent. The first arrivals were around 23 October and by the end of the month we were looking at what was potentially another large invasion, certainly the Waxwing Winter was on the cards for the whole country. The majority of the birds were at the expected locations in Scotland and along the E coast, however there was a bird reported (during BBC’s Autumnwatch) flying over Arne, Dorset.
As the Waxwing winter progressed into November the wind direction changed to a NE, this helped to bring more birds across and push the Waxwing Front towards the SW as we would normally expect. By this time many birders were finding flocks – although unlike previous winters these flocks were of small numbers – many people were lucky if they found birds in the double figures.
Then as we approached December things changed, for birders in the south anyway. The Waxwing Front halted in northern England. The cause for this was a change in the wind direction, from NE the UK was now having some unseasonably warm weather and southerlies. The southerlies acted as a barrier for the birds in the country heading south so they decided to stay put and enjoy the bumper crop of berries in Scotland and Northern England.
Whilst the southerlies put a hold on birders in the south getting Waxwings, we knew one way or other given the numbers in the country (albeit somewhat modest compared to previous invasions in 2010 and 2012) we would get them. It would come down to one of two things happening – a change in wind direction and/or the consumption of all the berries in the north.
We didn’t have long to wait though, around Christmas the Waxwing front started swinging round to the SW and the Waxwing winter was back in full swing across the country and by the middle of January 2017 almost every single county in the UK had a report of at least one Waxwing.
In the maps below which are based on reports of Waxwings throughout the winter, I show the general wind direction (arrow) and the movement of the Waxwings (in orange) where the solid orange represents a good chance of there being a Waxwing in that area. The solid orange line represents the main “Waxwing Front” indicating the division between very few birds ahead of the front and the majority behind the front. The dots ahead of the front indicate the location where some birds had been reported.
Now, I’ve sort of had a very interesting experience with Waxwing this year, missing them in the New Year in Kent, and very few actually making it into Berkshire. However, the last weekend I headed over the Slimbridge and saw some Waxwings on route. Typically, one week later a group of 4 turned up in Bracknell and stayed for several weeks feeding on apples. This meant I was able to get some good views and (albeit not as good as 2012/13) some decent photos too (see below).
The Waxwing Winter is currently on going with many still around the country feasting on either the berries or apples – so keep an eye out for them. Meanwhile at this time of year as a birder my attention turns back to summer as the spring migration has started with the first few summer migrants now beginning to arrive – it’s now a case of keeping an eye out for southerlies on the charts and an eye on reports from N Africa, Spain and France.
Whilst spring migration has started, my next blog is actually going to be about a bird that has caused a bit of a stir in Stow-on-the-Wold – the Blue Rock Thrush.